Method of manufacturing a flat wiper blade assembly

ABSTRACT

A heavy-duty flat wiper blade assembly has a wiper element and an extruded metallic frame. The frame has a bottom channel with a slot traversing its length in which the wiper element is maintained. The wiper element extends through the slot and outwardly from the bottom channel to make contact with a surface to be wiped. The frame has a closed upper channel that may include a fluid inlet opening for receiving wiper fluid into the channel and a fluid outlet opening for discharging the wiper fluid from the upper channel onto a surface to be wiped.

RELATED APPLICATIONS

This application is a divisional of application Ser. No. 10/103,477,filed Mar. 21, 2002 now U.S. Pat. No. 6,766,553.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to heavy-duty flat wiper bladeassemblies.

2. Related Art

Heavy-duty flat wiper blade assemblies are known having a straight bodymounting a rubber wiper element. In one known construction, the body isextruded from a plastic which is, in turn, reinforced by a metalstiffener to provide sufficient structural rigidity to the body, asshown in U.S. Pat. No. 3,107,384. In another known construction, thebody is fabricated from a strip of steel which is bent into a generallyU-shaped profile in cross-section and crimped along its length to therubber wiper element to secure the wiper element. In this case, the flatsteel body component is cut to length along with the wiper element priorto folding the flat steel over the wiper element.

Both such constructions are costly to manufacture and are limited in thefeatures and advantages they can offer.

Heavy-duty flat wiper blade assemblies constructed according to thepresent invention overcome or greatly minimize the foregoing limitationsof prior wiper blade assemblies.

SUMMARY OF THE INVENTION

A heavy-duty flat wiper blade assembly has a wiper element and anextruded metallic frame. The frame has a bottom channel with a slot andan upper channel separate from the bottom channel. The wiper element isdisposed in the bottom channel and extends through the slot to makecontact with a surface to be wiped. The upper channel is closed and mayoptionally be provided with a fluid inlet opening for receiving wiperfluid into the channel and a fluid outlet opening for discharging thewiper fluid from the upper channel and onto a surface to be wiped.

Additionally, a method for manufacturing a wiper blade is providedwherein a wiper element is slidably inserted into a bottom channel of anextruded metallic frame. The wiper element depends from the bottomchannel and through a slot in the bottom channel to make wiping contactwith a surface to be wiped. A wall of the bottom channel is then stakedto fix the wiper element within the bottom channel. An optional methodeliminates the staking step and installs a pair of end plugs into eachend of the frame to releasably maintain the wiper element within thebottom channel.

Some advantages of the invention include providing for increasedefficiencies in the manufacture and assembly of a heavy-duty wiper bladeassembly by reducing the number of operations required to produce thewiper blade assembly, by reducing the scrap, by improving the handlingof the wiper blade components during assembly and by reducing the timerequired for assembly, thus reducing the total costs of producing thewiper blade assembly.

Another advantage of the invention is the ability to utilize the closedupper channel as a passage for conveying wiper fluid from which thefluid may be dispensed directly on the surface to be wiped.

Another advantage of the invention is a reduction in the amount ofmaterial used in the wiper element.

THE DRAWINGS

These and other features and advantages of the present invention willbecome more readily appreciated when considered in connection with thefollowing detailed description and appended drawings, wherein:

FIG. 1 is a perspective view of a wiper blade assembly showing a firstpreferred embodiment of the present invention;

FIG. 2 is a cross-sectional view taken generally along lines 2—2 of FIG.1;

FIG. 3 is a front elevation view of a second embodiment of the presentinvention;

FIG. 4 is a fragmentary isometric view of the blade assembly of FIG. 3;

FIG. 5 is a cross-sectional view taken generally along lines 5—5 of FIG.4;

FIG. 6 is a cross-sectional view taken generally along lines 6—6 of FIG.4; and

FIG. 7 is an enlarged fragmentary elevation view, shown partly insection, of FIG. 4.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a heavy-duty wiper blade assembly 10 constructedaccording to a first preferred embodiment of the present invention. Thewiper blade assembly 10 has an extruded frame 12 having a bottom channel14 that receives a wiper element 16, and an upper channel 18 that isseparate from the bottom channel 14. The wiper element 16 is slidablyreceived in the bottom channel 14 and is maintained in the bottomchannel 14 by a protuberance or preferably a plurality of protuberances20.

The frame 12 of the wiper blade assembly 10 is extruded into oneinternal member from a metallic material, such as aluminum, or any otherextrudable metallic material. The finished frame 12 has a pair of ends24, 26. The bottom channel 14 and upper channel 18 extend between theends 24, 26.

The bottom channel 14 has slot 28 formed along the bottom channel 14between the pair of ends 24, 26 having openings 27, 29 such that abottom surface 30 of the bottom channel 14 preferably has a pair ofopposing lips 31, 32 extending generally toward one another, thuscausing the bottom channel 14 to be generally C-shaped in cross-section,as shown best in FIG. 2.

The upper channel 18 of the frame 12 is a generally closed channel otherthan openings 34, 36 at the ends 24, 26 of the frame 12, and an aperture38 formed in a sidewall or opposing sidewalls 40, 42 of the upperchannel 18 between the ends 24, 26 of the frame 12.

The aperture 38 formed in the opposing sidewalls 40, 42 of the upperchannel 18 is preferably formed equidistant from either end 24, 26 andreceives a mounting pin (not shown) therethrough so that the wiper bladeassembly 10 can be attached to a wiper arm (not shown).

As best shown in FIG. 2, the wiper element 16 has a crown portion 44, aneck portion 46, a bumper portion 48, a hinge portion 50, and a bodyportion 52. The wiper element 16 is received by the bottom channel 14 bysliding the crown portion 44 of the wiper element 16 into one of theopenings 27, 29 of the bottom channel 14. The pair of opposing lips 31,32 forming the bottom surface 30 of the bottom channel 14 extendgenerally inwardly toward the neck portion 46 such that they capture andreleasably maintain the wiper element 16. Though the wiper element 16 isreleasably maintained within the channel 14 by the lips 31, 32, thewiper element 16 is still able to slide transversely within the bottomchannel 14.

Preferably, the crown portion 44 of the wiper element 16 conformsgenerally in shape to the bottom channel 14. A bottom surface 53 of thecrown portion 44 is preferably in mating contact with an upper surface54 of the lips 31, 32 such that the crown portion 44 is maintainedwithin the bottom channel 14 during assembly 10. The neck portion 46 ofthe wiper element 16 depends from the crown portion 44 and passesbetween the lips 31, 32 of the frame 12 and joins the bumper portion 48of the wiper element 16. The bumper portion 48 of the wiper element 16contacts the bottom surface 30 of the lips 31, 32. The wiper element 16can be secured against relative sliding movement within the channel 14by staking a side-wall or sidewalls 40, 42 of the bottom channel 14,such that a plurality of protuberances 20 extend laterally inwardly intogripping engagement with the crown portion 44 of the wiper element 16.As shown in FIG. 1, preferably two protuberances 20 are staked adjacenteach end 24, 26 of each side-wall 40, 42 of the frame 12. However, itshould be recognized that any number of protuberances 20 may be stakeddepending on the requirements of the wiper blade application.

FIGS. 3–7 show an alternative embodiment of a wiper blade assembly ofthe invention generally at 110. The same reference numerals are used todesignate like features to those of the first embodiment, but are offsetby 100. The assembly 110 includes an upper channel 118 in which a pairof end plugs 22, 23 are installed. The channel 118 communicates with asource of pressurized wiper fluid (not shown) through one of the endplugs 22, 23. The wiper fluid can travel through and be dispensed fromthe upper channel 118 directly onto the surface to be wiped by the wiperblade assembly 110. Also, the wiper element 116 is preferably releasablymaintained in the bottom channel 114 by a bottom portion 56 of the pairof end plugs 22, 23, thus enabling the wiper element 116 to be quicklyand easily replaced when needed. It should be recognized however, that astaking operation could be used here as performed in the first preferredembodiment.

The pair of end plugs 22, 23 are preferably sized so that they can bepress fit into the openings 134, 136 at the ends 124, 126 of the upperchannel 118 such that they have an interference fit or other suitablemechanical retention (e.g. latches), and create a generally fluid tightseal therein. The end plugs 22, 23 are shaped to have a plug portion 58that fits within the upper channel 118, and a face portion 60 thatremains in mating contact with an end 124, 126 of the frame 112. One endplug 22 preferably has a through hole 62 such that a hose 64 can beconnected in the through hole 62 of the end plug 22 to provide forcommunication of fluid between the upper channel 118 and the source ofpressurized wiper fluid. The wiper fluid can then be received within theupper channel 118 of the wiper blade assembly 110 and be dispensed fromthe upper channel 118 through a nozzle 64 and directed onto the surfaceto be wiped by the wiper blade assembly 110. It should be recognizedhowever, that the hose 64 could be received in an opening anywhere alongthe upper channel 118 between the two ends 24, 26 of the upper channel118, and not through one of the end plugs 22, 23 in the pair of ends124, 126 of the frame 112.

The end plugs 22, 23 preferably extend downwardly from the upper channel118 so that the face portion 60 blocks or covers at least a portion ofthe bottom channel 114. With at least one end plug 22, 23 removed fromthe bottom channel 114, the wiper element 116 can be slidably receivedwithin the bottom channel 114, and the end plug or end plugs 22, 23 canthen be press fit into the bottom channel 114. The face portions 60 ofthe plugs 22, 23 then releasably maintain the wiper element 116 withinthe bottom channel 114. If the wiper element 116 needs replacing, one ofthe end plugs 22, 23 can simply be removed to slidably remove the wiperelement 116 from the bottom channel.

As best shown in FIG. 6, another opening 66 in one of the side walls 40,42 of the upper channel 118 has the nozzle 64 received therein. Thenozzle 68 is fixed in the opening 66 of the upper channel 118 such thatthe nozzle 68 is maintained in sealing engagement with the opening 66.The nozzle 64 has a through hole 69 that is formed to dispense wiperfluid from the upper channel 118 such that the wiper fluid exitspreferably in a desired spray pattern. The nozzle 68 is shown here to begenerally equidistant between the two ends 24, 26 of the upper channel118. It should be recognized however, that the opening 66 used toreceive the nozzle 68 can be placed anywhere along the length betweenthe two ends 24, 26 of the upper channel 118, as best suited for theapplication. It should also be recognized that any number of nozzles 68can be employed within the sidewalls 140, 142 to insure adequatecoverage of wiper fluid on the surface to be wiped by the wiper bladeassembly 110.

As best shown in FIG. 5, a grommet 70 is installed in the aperture 138to create a fluid tight seal between the mounting pin and the upperchannel 118 to prevent any wiper fluid from leaking between the aperture138 and the mounting pin. Ends 72, 74 of the grommet 70 are formed withradially enlarged flanges 76, 78 for securing and sealing the grommet 70within the aperture 138. The grommet 70 has a tubular body passingthrough the upper channel 118, defining a through hole 80 foraccommodating the mounting pin (not shown). Other suitable means forcreating a seal between the aperture 138 and the mounting pin to preventwiper fluid from exiting the aperture 138 is contemplated by thisinvention, such as applying a coating to the walls of the aperture 138or to the mounting pin so that the coating provides a fluid-tight seal.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described. The inventionis defined by the claims.

1. A method of manufacturing a flat wiper blade assembly, comprising:forming a wiper element; extruding a metallic frame having a generallyclosed upper channel and an open bottom channel with a slot transversinga wall spanning the length of the bottom channel to receive the wiperelement; slidably inserting the wiper element into the bottom channel ofthe frame so that the wiper element depends from the bottom channel andthrough the slot to make wiping contact with a surface to be wiped;installing a pair of end plugs into an opening at each end of the upperchannel and across at least a portion of the bottom channel toreleasably maintain the wiper element within the bottom channel;providing a hose and a nozzle; forming an opening in a sidewall of theupper channel; connecting the hose to the upper channel so as to beoperative to provide for fluid communication between the upper channeland a source of wiper fluid under pressure provided through the hose;and inserting the nozzle into the opening in the upper channel so thatwiper fluid can be dispensed through the nozzle and onto a surface to bewiped.
 2. The method of manufacturing a flat wiper blade assembly ofclaim 1, further comprising: providing a grommet having a through hole;forming an aperture in at least one sidewall of the upper channel;inserting the grommet into the aperture so that the grommet ismaintained within the aperture and provides for a fluid tight sealbetween a mounting pin passing through the hole in the grommet and theaperture.
 3. A method of manufacturing a flat wiper blade assembly,comprising: extruding a rigid metallic frame extending longitudinallybetween opposite ends with an open bottom channel having a pair oflaterally spaced side walls and a bottom wall formed with alongitudinally extending slot, and an upper channel having a partitionwall separating said upper channel from said bottom channel, and a pairof laterally spaced side walls of said upper channel extending upwardlyfrom said partition wall, and a top wall extending between said sidewalls and spaced from said partition wall to enclose said upper channel,and mechanically deforming a protuberance extending laterally from aside wall of said bottom channel, disposing a resilient wiper elementextending longitudinally and having a crown, a neck and a body in saidbottom channel with said neck extending through said slot and said bodyextending below said frame with said protuberance extending laterallyinwardly into gripping engagement with said wiper element to secure saidwiper element against longitudinal movement relative to said bottomchannel.
 4. A method of manufacturing a flat wiper blade assembly,comprising: extruding a rigid metallic frame extending longitudinallybetween opposite ends with an open bottom channel having a pair oflaterally spaced side walls and a bottom wall formed with alongitudinally extending slot, and an upper channel having a partitionwall separating said upper channel from said lower channel, and a pairof laterally spaced side walls of said upper channel extending upwardlyfrom said partition wall, and a top wall extending between said sidewalls and spaced from said partition wall to enclose said upper channel;and forming a fluid inlet opening in said upper channel for receivingwiper fluid within said upper channel, forming a fluid outlet openingfor discharging wiper fluid from said upper channel, and disposing afluid nozzle communicating with said fluid outlet opening.
 5. A methodof manufacturing a flat wiper blade assembly, comprising: extruding arigid metallic frame extending longitudinally between opposite ends withan open bottom channel having a pair of laterally spaced side walls anda bottom wall formed with a longitudinally extending slot, and an upperchannel having a partition wall separating said upper channel from saidlower channel, and a pair of laterally spaced side walls of said upperchannel extending upwardly from said partition wall, and a top wallextending between said side walls and spaced from said partition wall toenclose said upper channel; and forming a mounting aperture in said sidewalls of said upper channel for receiving a mounting pin.